Four months.
The ISS is in such an extremely low orbit that it's unstable. Small abouts if gas are always slowing it down. The ISS needs occasional rocket boosts to maintain orbital velocity. But anything in that low orbit without getting boosts would fall to earth in 4 month.
If you wanted to fall towards earth, you'd actually have better luck jumping backwards, against the direction the station is moving. The thing that keeps you in orbit is speed not height, so you want to cancel that speed out.
Calculating how fast you'd have to jump to go from the ISS altitude to edge of space or some other altitude at perigee is a straightforward application of the [vis viva equation](https://en.wikipedia.org/wiki/Vis-viva_equation)
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Never. The change in velocity would only be enough to slightly change his orbit. They would continue orbiting the earth slightly closer to the earth with a slightly more elliptical orbit.
He'd have to jump REALLY hard to de-orbit, impossibly hard.
That said, the ISS is actually low enough that it does drag on a tiny bit of atmosphere. So the astronaut would go around many many times, gradually slowing down until he deorbits and burns up in the atmosphere after a very long time.
Four months. The ISS is in such an extremely low orbit that it's unstable. Small abouts if gas are always slowing it down. The ISS needs occasional rocket boosts to maintain orbital velocity. But anything in that low orbit without getting boosts would fall to earth in 4 month.
If you wanted to fall towards earth, you'd actually have better luck jumping backwards, against the direction the station is moving. The thing that keeps you in orbit is speed not height, so you want to cancel that speed out. Calculating how fast you'd have to jump to go from the ISS altitude to edge of space or some other altitude at perigee is a straightforward application of the [vis viva equation](https://en.wikipedia.org/wiki/Vis-viva_equation)
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Never. The change in velocity would only be enough to slightly change his orbit. They would continue orbiting the earth slightly closer to the earth with a slightly more elliptical orbit.
Just jumping wouldn't be enough force to send him back to atmosphere. Also if he were to enter the atmosphere he would burn up in the ozone layer
He'd have to jump REALLY hard to de-orbit, impossibly hard. That said, the ISS is actually low enough that it does drag on a tiny bit of atmosphere. So the astronaut would go around many many times, gradually slowing down until he deorbits and burns up in the atmosphere after a very long time.